FOLLICLE GROWTH IN THE IMMATURE RAT OVARY

1978 ◽  
Vol 88 (2) ◽  
pp. 375-382 ◽  
Author(s):  
A. J. Hage ◽  
A. C. Groen-Klevant ◽  
R. Welschen

ABSTRACT In ovaries of immature rats the following parameters were estimated from autoradiographs prepared after pulse labelling with tritiated thymidine: 1) The time it takes follicles to grow from one stage of development to another. This could be derived from the total number of granulosa cells in these stages and from their doubling times. The doubling time of granulosa cells was determined from their labelling index and the duration of their DNA-synthesis phase. 2) The number of follicles present in the ovary at different ages. 3) The number of follicles, which start on their development at different ages. It was found, that more follicles start to grow in 8 and 16 days old rats (2.0/h) than in 28 days old ones (1.0/h). Moreover, the follicles grow somewhat faster earlier in life than later. The development from a follicle with one layer of granulosa cells to one with several layers and antrum formation takes about 15 days in the first half of the period of immaturity while it takes about 17 days as the animal approaches maturity.

1969 ◽  
Vol 62 (1) ◽  
pp. 117-132 ◽  
Author(s):  
Torben Pedersen

ABSTRACT The growth of follicles in the immature mouse ovary was investigated in autoradiographs prepared after pulse-labelling with tritiated thymidine. Three parameters, which determine follicle growth were estimated: The number of follicles present in the ovary at different ages. The time it takes follicles to grow from one stage of development to another. This was calculated from the total number of granulosa cells in these stages and from their doubling times. The doubling time of granulosa cells was determined from their labelling index and the duration of their DNA-synthesis phase. The number of follicles, which start on their development at different ages. It was found, that the follicle development is not constant in the period from birth to maturity, but varies considerably. More follicles start to grow in the young than in the older immature mouse. Moreover the follicles grow faster early in life than later. The development from a follicle with one layer of granulosa cells to one with several layers and antrum formation takes about 10 days in the first half of the immature period, while it takes about 16 days as the animal approaches maturity. It was furthermore shown, that about 850 follicles start to grow in the immature period.


1981 ◽  
Vol 96 (3) ◽  
pp. 377-381 ◽  
Author(s):  
A. C. Groen-Klevant

Abstract. Follicle growth in the ovaries of cyclic rats was studied by autoradiography after pulse labelling with [3H]thymidine: growth rates and numbers were determined for follicles of the types 3b to 6 (type 3b: follicles with 1 –2 layers of granulosa cells; type 6: follicles with a diameter of 200 μm and usually with a single antrum). The data indicate a total time of follicle development, from type 3b to ovulation, of 22 days. Growth of follicles of the types 3b to 6 in these cyclic rats was roughly similar to that in late prepubertal animals, previously studied. However, some changes of the growth of these types of follicles, related to the stages of the cycle, could be noted.


1970 ◽  
Vol 64 (2) ◽  
pp. 304-323 ◽  
Author(s):  
Torben Pedersen

ABSTRACT The variations in size, numbers and growth rates of mouse ovarian follicles were investigated at different stages of the oestrous cycle. Autoradiographs were prepared of sections of ovaries after pulse-labelling with tritiated thymidine. By determining the growth rate of the granulosa cells expressed as their doubling times, it was possible to estimate the exact growth rates of whole follicles. The number of follicles which began developing during a particular time interval was also determined. The results show that the number of large follicles fluctuates with the cycle, and that the size of the largest follicles increases during the cycle. Follicles of medium size grow faster at oestrus that at any other time. This is in contrast to the large follicles, in which only minor variations in growth rate were noted. It was moreover shown, that more follicles begin to grow at oestrus than at other periods during the cycle. It was concluded, that the reduction in the number of small follicles with age is mainly due to follicle development rather than to the degeneration of small follicles. The time required for the full development of an ovarian follicle is 19 days.


Endocrinology ◽  
2007 ◽  
Vol 148 (8) ◽  
pp. 3711-3721 ◽  
Author(s):  
Ann E. Drummond ◽  
Marianne Tellbach ◽  
Mitzi Dyson ◽  
Jock K. Findlay

Fibroblast growth factor 9 (FGF9) is widely expressed in embryos and fetuses and has been shown to be involved in male sex determination, testicular cord formation, and Sertoli cell differentiation. Given its male gender bias, the ovary has not been reported to express FGF9, nor has a role in ovarian function been explored. We report here that FGF9 mRNA and protein are present in the rat ovary and provide evidence that supports a role for FGF9 in ovarian progesterone production. FGF9 mRNA levels as determined by real-time PCR were high in 4-d-old rat ovaries, thereafter declining and stabilizing at levels approximately 30% of d 4 levels at d 12–25. Levels of FGF9 mRNA in the ovary were significantly higher than that present in adult testis, at all ages studied. The FGF9 receptors FGFR2 and FGFR3 mRNAs were present in postnatal and immature rat ovary and appeared to be constitutively expressed. FGF9 protein was localized to theca, stromal cells, and corpora lutea and FGFR2 and FGFR3 proteins to granulosa cells, theca cells, oocytes, and corpora lutea, by immunohistochemistry. Follicular differentiation induced by gonadotropin treatment reduced the expression of FGF9 mRNA by immature rat ovaries, whereas the estrogen-stimulated development of large preantral follicles had no significant effect. In vitro, FGF9 stimulated progesterone production by granulosa cells beyond that elicited by a maximally stimulating dose of FSH. When the granulosa cells were pretreated with FSH to induce LH receptors, FGF9 was found not to be as potent as LH in stimulating progesterone production, nor did it enhance LH-stimulated production. The combined treatments of FSH/FGF9 and FSH/LH, however, were most effective at stimulating progesterone production by these differentiated granulosa cells. Analyses of steroidogenic regulatory proteins indicate that steroidogenic acute regulatory protein and P450 side chain cleavage mRNA levels were enhanced by FGF9, providing a mechanism of action for the increased progesterone synthesis. In summary, the data are consistent with a paracrine role for FGF9 in the ovary.


1973 ◽  
Vol 72 (3) ◽  
pp. 425-437 ◽  
Author(s):  
Lars Hamberger ◽  
Hans Herlitz ◽  
Anita Sjögren

ABSTRACT Ovaries from rats varying in age between 5–12 days were incubated in Krebs bicarbonate buffer at 37°C containing 5.5 mmol/l glucose. A 2 h incubation in the presence of 0.01 μg/ml LH (NIH-LH-B6) caused an increase in lactic acid production as compared to controls, and a clear dose-response was demonstrated up to 100 μg/ml. In vitro the addition of 100 μg/ml FSH (NIH-FSH-S5) or 10 mmol/l cyclic AMP also caused stimulatory effects on lactate production. In experiments with ovaries from 8–9 day old rats, incubations were carried out in a medium containing 0.1 mmol/l [14C]AIB (α-aminoisobutyric acid), and the distribution ratios for this model amino acid were determined after 2 h incubation in the absence and presence of LH, FSH or cyclic AMP respectively. No hormonal effects were demonstrated, while cyclic AMP caused a significant increase in the [14C]AIB uptake. In further experiments ovaries from 9 day old rats were incubated in medium containing both [14C]AIB (0.1 mmol/l) and [3H]leucine (0.03 mmol/l). Four hours before the removal and incubation of the ovaries the rats were injected ip with FSH or LH (500 μg/100 g body weight) or saline. The distribution ratios of both [14C]AIB and [3H]leucine were significantly elevated in the FSH injected group while LH was ineffective. In similar experiments with 0.01 mmol/l [3H]proline it was also possible to demonstrate an increased incorporation of this amino acid into ovarian protein after a single FSH injection 2 h before the incubation.


1995 ◽  
Vol 132 (1) ◽  
pp. 97-102 ◽  
Author(s):  
Mitsuko Kobayashi ◽  
Mareo Yamoto ◽  
Sawako Minami ◽  
Miyako Imai ◽  
Ryosuke Nakano

Kobayashi M, Yamoto M, Minami S, Imai M, Nakano R. Immunohistochemical localization of inhibin α- and βA-subunits in the ovary of immature female rats. Eur J Endocrinol 1995;132:97–102. ISSN 0804–4643. Immunohistochemical localization of inhibin α- and βA-subunits was examined in the ovaries of immature female rats. The granulosa cells in various sized ovarian follicles obtained from rats that were 10–24 days old exhibited positive staining for inhibin α- and βA-subunits. The relative intensities of immunostaining for α- and βA-subunits increased during follicular growth and maturation. Ova and internal thecal cells did not show any immunostaining for inhibin α- and/or βA-subunits. These results suggest that granulosa cells of immature rat ovaries may produce inhibin from the 10th day after birth, and that an increase in the number of mature ovarian follicles results in an increase in inhibin production in the immature rat ovary during prepubertal development. Mitsuko Kobayashi, Department of Obstetrics and Gynaecology, Wakayama Medical College, 1 shichibancho, Wakayama 640, Japan


1994 ◽  
Vol 140 (3) ◽  
pp. 409-417 ◽  
Author(s):  
S A Ghersevich ◽  
M H Poutanen ◽  
H J Rajaniemi ◽  
R K Vihko

Abstract Antibodies against human placental 17β-hydroxysteroid dehydrogenase (17-HSD) and 17-HSD cDNA were used to study the expression of the corresponding enzyme in the immature rat ovary during follicular development and luteinization, which were induced by treating the animals with pregnant mare serum gonadotrophin (PMSG) or with PMSG followed by human chorionic gonadotrophin (hCG). Immuno-blot analysis indicated that the Mr of the 17-HSD expressed in rat granulosa cells was 35 000, as previously shown for the human placental enzyme. In immunohistochemical studies of untreated immature rat ovaries, only the granulosa cells from small antral follicles were stained. One day after PMSG treatment, strong expression of 17-HSD was observed in the granulosa cells of growing Graafian follicles. A marked decrease in enzyme expression was observed in preovulatory follicles on day 2 of PMSG treatment, starting from the basal layers of granulosa cells and progressing toward the luminal cells. No 17-HSD expression was detected in luteinized follicles or corpora lutea 22 h after hCG injection. The stroma and theca cells were negative for 17-HSD staining. In Northern hybridization analyses, two 17-HSD mRNAs were detected (1·4 and 1·7 kb). The strongest expression for both mRNAs was detected after 1 day of PMSG treatment, coinciding with maximal immunostaining of the enzyme protein. Down-regulation of 17-HSD observed by immunohistochemistry was reflected in a similar decrease in mRNA expression and the signals were almost undetectable 22 h after hCG injection. Our data suggest that 17-HSD expression in rat granulosa cells is up-regulated during follicular development and, thereafter, the enzyme expression is down-regulated during luteinization. Journal of Endocrinology (1994) 140, 409–417


2004 ◽  
Vol 16 (9) ◽  
pp. 218
Author(s):  
A. E. Drummond ◽  
M. Dyson ◽  
J. K. Findlay

FGF9, a member of the fibroblast growth factor family (FGF), is known to be a male sex-determining factor involved in testicular cord formation (1). FGF9 knockout males are sex-reversed (2). However, nothing is known about FGF9's role in folliculogenesis because these mice die at birth (2). We previously reported the presence of FGF9 mRNA and protein in the immature rat ovary (3). In these studies we investigated: (1) the presence of FGF9 receptors (FGFR3) on granulosa cells (GC); and (2) the impact of FGF9 on GC progesterone production. GC isolated from 21 day old diethylstilboestrol (DES)-treated rats were cultured for either 2 hours (RNA) or 2 days (progesterone) in McCoys 5C with FGF9 (0.1-50ng/ml) � FSH (100ng/ml). Progesterone was measured in conditioned media by radioimmunoassay. RNA was extracted from the granulosa cells and reverse-transcribed for PCR. Specific primers for P450 side chain cleavage (SCC) amplified a 329�bp cDNA fragment. GAPDH was used for data normalisation. The FGF9 receptor FGFR3, was immunolocalised on formalin-fixed, paraffin-embedded sections of immature rat ovary. FGFR3 protein was localised only to GC of the ovary. Progesterone production by cultured GC was significantly elevated by FGF9, consistent with the presence of FGFR3. Relative to a maximally stimulating dose of FSH, FGF9 increased progesterone production 10- fold. In preliminary studies, FGF9 increased the expression of P450 SCC mRNA by cultured GC revealing a mechanism by which FGF9 increases progesterone production. These data suggest a role for FGF9 not just in testicular formation, but in the regulation of ovarian steroidogenesis. Supported by the NH&MRC of Australia (Regkey 241000 & 198705). (1) Cotinot et al. (2002) Semin. Reprod. Med. 20, 157. (2) Colvin et al. (2001) Cell 104, 875. (3) Drummond et al. (2003) SRB Abstract 90.


2006 ◽  
Vol 191 (3) ◽  
pp. 549-558 ◽  
Author(s):  
Mehmet Uzumcu ◽  
Peter E Kuhn ◽  
Jason E Marano ◽  
AnnMarie E Armenti ◽  
Lisa Passantino

Methoxychlor [1,1,1-trichloro-2,2-bis(4-methoxyphenyl) ethane; MXC] is a chlorinated hydrocarbon pesticide commonly used in the United States as a replacement for DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane]. While MXC is a weak estrogenic compound, its more active, major metabolite [2,2-bis(p-hydroxyphenyl)-1,1,1-trichloroethane; HPTE] shows estrogenic, anti-estrogenic, or anti-androgenic properties depending on the receptor subtype with which it interacts. Anti-Mullerian hormone (AMH) is a paracrine factor that suppresses initial follicle recruitment in the ovary. Studies have shown the effects of exposure to MXC on adult ovarian morphology and function. However, the effect of exposure to MXC at an early postnatal stage on pre-pubertal follicular development and ovarian AMH production has not been studied. Around postnatal day (P) 4, most of the primordial follicular assembly in rats is complete, and a large number of primordial follicles transition into the primary follicle stage, a process that is inhibited by estrogen. The objective of this study was to examine the effect of early postnatal (P3–P10) MXC exposure on ovarian morphology and size, follicle number, and AMH production in the pre-pubertal (P20) rat ovary and to investigate the effect of HPTE on AMH production in immature rat granulosa cells in vitro. Female rats were injected (s.c.) daily with vehicle (control) or 1, 10, 50, 100, or 500 mg MXC/kg per day (referred to here as 1MXC, 10MXC, and so forth.) between P3 and P10. On P20, uterine and ovarian weights were determined, ovarian histology was examined, and follicles were counted and classified into primordial, primary, secondary, pre-antral, or antral stages using the two largest serial sections at the center of the ovary. Ovarian AMH production was examined using immunohistochemistry and western blot analysis. The effect of HPTE (0.5–25 μM) on AMH production in cultured immature rat granulosa cells was determined by western blot analysis. Ovarian weight was reduced by 50, 100, and 500MXC (P < 0.01). MXC treatment inhibited folliculogenesis. Both 100 and 500MXC had a reduced number of antral follicles (P < 0.05) with a concomitant increase in pre-antral follicles (P < 0.05). Follicle numbers were not significantly affected by 1, 10, or 50MXC. Total follicle number and the number of primordial, primary, or secondary stage follicles were not significantly different in all treatment groups. Immunohistochemistry showed that MXC-treated ovaries had more AMH-positive follicles with stronger AMH immunostaining. Western blot analysis showed that AMH production was 1.6 ± 0.2, 1.85 ± 0.6, and 2.2 ± 0.5 times higher in the 50, 100, and 500MXC ovaries as compared with the control ovaries respectively (P < 0.05). Granulosa cells treated with 1 or 5 μM HPTE had significantly greater AMH production (P < 0.05). These results demonstrate that MXC inhibits early ovarian development and stimulates AMH production directly in the rat ovary. In addition, HPTE was shown to stimulate AMH production in rat granulosa cells. Endocrine disruptors are widespread in the environment, and MXC represents a model endocrine disruptor due to the multiple actions of its metabolites. This study confirms that the endocrine disruptor MXC inhibits follicular development and demonstrates for the first time that MXC and HPTE directly stimulate AMH productionin the ovary. Thisnovel finding suggests that elevated AMH may play a role in MXC’s inhibitory effect in the ovary.


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